Closure cap for the cooling systems of internal combustion engines



Dec. 23, 1958 s, GORST T 2,865,531

' CLOSURE CAP FOR THE COOLING SYSTEMS 0F INTERNAL COMBUSTION ENGINES Filed June 2, 1955 v 2 Sheets-Sheetl ttorney 1958 .1. R. s. GORST ET AL 2,865,531

CLOSURE CAP FOR THE COOLING SYSTEMS OF INTERNAL COMBUSTION ENGINES Filed June 2, 1955 2 Sheets-Sheet 2 Attorney United States Patent CLOSURE CAP FOR THE COOLING SYSTEMS OF INTERNAL COMBUSTION ENGINES James R. S. Gorst, Chandlers Ford, and Stanley W. Kemp,

Totton, England, assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application June 2, 1955, Serial No. 512,832

Claims priority, application Great Britain June 8, 1954 1 Claim. (Cl. 220-44) This invention relates to closure caps for the cooling systems of internal combustion engines.

Some closure caps embody two valves; a main valve held on its seating under spring pressure and a secondary valve designed to relieve sub-atmospheric pressure in the cooling system. This invention is concerned with the form of the secondary valve.

According to the invention there is a closure cap for internal combustion engine cooling systems, having a spring-pressed primary valve member within which is a secondary valve member in the form of a freely floating disc movable between two relatively fixed parts of the primary valve member.

The disc is preferably of rubber or like material, and preferably seats, when closed, against a shoulder forming one of said fixed parts inside the primary valve member; and rests when open, on a raised part of the other of said fixed parts. The raised part is preferably formed around an aperture in the other fixed part and there can be a number of smaller apertures spaced around the raised part.

The secondary valve of this invention is particularly, but not exclusively, adapted for use in a closure cap such as is described and claimed in the specification of General Motors Corporation British Patent No. 511,007 (corresponding with the United States Patent 2,164,450 granted July 4, 1939) in which the primary valve member is domed and is loosely and pivotallymounted at its upper end on a stud inside the cap.

The scope of the invention is defined in the appended claims; and how it can be carried into eifect is hereinafter particularly described with reference to the accompanying drawings in which:

Fig. 1 is a sectional elevation of one embodiment of a closure cap fixed on the filler spout of an engine cooling system;

Fig. 2 is a view similar to Fig. l but showing the position of the secondary valve when the engine coolant vaporises and creates pressure in the cooling system; and

Fig. 3 is a side elevation of a portion of an internal combustion engine cooling system.

In the embodiment of the invention shown in Figs. 1 and 2 a closure cap comprises a cover 1 having at its lower edge a pair of inturned tabs 2 adapted to engage, as shown, flanges 3 on a filler spout 4 which is vented at 5 and secured on the top wall of a radiator inlet header 6, the flanges 3 serving as elements of a well known type of quickly detachable bayonet connection in cooperation with the tabs 2. The central portion of the cap cover 1 is depressed at 7 and carries a riveted stud 8 dependent therefrom. The depression 7 provides a working clearance between a spring disc 9 and a ridge seat 10 on the spout 4, the spring disc 9 being formed with a central annular depression 11 forming a seat for the upper end of a coil spring 12, the lower end of which is seated on an annular shoulder 13 near the top of a domed primary valve member 14. The top of the valve member 14 is 2,865,531 Patented Dec. 23, 1958 formed with a central aperture whereby it is slidably and pivotally fixed on the stud 8, and with a series of small holes 15 about said central aperture.

The primary valve member 14 has a lower out-turned flange 16 and press-fitted within the lower end of the domed primary valve member 14 is a smaller domed part 17 also having an out-turned flange 18 at its lower end.

Between the out-turned flange 16 on the primary valve member 14 and the out-turned flange 18 on the smaller domed part 17 is an annular rubber valve washer 19 which is adapted to abut a seat 20 in the neck of the radiator filler spout 4 thereby forming the primary valve.

The shoulder 13 formed in the wall of the primary domed valve member 14 acts as a, fixed part of the primary valve member 14 between which and the upper surface of the smaller domed part 17 is retained a freely floating rubber disc 21. The rubber disc 21 normally rests on a raised part 22 of the upper surface of the smaller domed part 17. The raised part 22 is formed round a central aperture 23 and smaller apertures 24 are spaced around and below the raised part 22.

The position of the cap cover 1 and the inlet header ice 6 in relation to the radiator 25 of the cooling circuit of an engine 26 is shown in Fig. 3. v

In operation the cap is secured on to the filler spout 4 thereby compressing the coil spring 12 and seating spring disc 9 on ridge seat 10 and causing the domed valve member 14 to slide up the dependent stud 8 forcing the head of the stud 8 into close proximity with the plane of the shoulder 13 (Fig. 1).

When the engine cooling system is not in operation the rubber disc 21 rests, as shown in Fig. 1, on the raised portion 22 of the domed part 17. When the cooling system is brought into operation and the coolant vaporises, the vaporised coolant will escape partly through the small apertures 24 but to a greater extent through the aperture 23, and thence through apertures 15 to vent 5, but as the pressure of the vaporised coolant increases the disc 21 will be forced upwardly 011 the raised portion 22 into engagement with the shoulder 13 in the wall of thedomecl primary valve member 14, the escape of coolant fluid then being prevented. When the pressure of the coolant fluid increases above a predetermined safe maximum pressure the primary valve member 14 is raised against the action of spring 12 to unseat the washer 19 from the seat 20 of the filler spout 4.

Thus the rubber washer 19 on the primary valve member 14 forms, with the seat 20 a primary valve, and the rullnber disc 21, with the shoulder 13 forms a secondary va ve.

On cooling, sub-atmospheric pressure is set up within the system and the rubber disc 21 falls or is sucked downwardly into contact with the raised part 22 on which it rests. Thus air is allowed to enter the system from the atmosphere through vent 5, and apertures 15 of the domed primary valve member 14, round the edge of the rubber disc 21 of the secondary valve and through the spaced smaller apertures 24, thereby relieving the sub-atmospheric pressure.

As shown in Fig. 2, the relative positions of the shoulder 13 and the lower end of the stud 8, when the cap is secured on the spout 4 are such that when the disc 21 seats on the shoulder 13 the central portion of the .disc lies in close proximity to the lower end of the stud 8. Thus, if the disc is bowed by the fluid pressure thereon it will be supported by contact with the stud 8. Also, upward movement of the primary valve member 14 when the coolant fluid pressure exceeds the predetermined safe limit will cause the disc 21 to be unseated from shoulder 13 by the stud 8. The same effect will also be achieved by downward movement of the cap and stud 8 when releasing the cap from the bayonet connection on the filler spout 4. In this way, accidental sticking of the disc 21 on shoulder 13 will be prevented.

We claim:

Aiclosure .device fora filler'spout of a cooling system in which said spout has a primary valve seat and a vent above said seat, said device comprising a cap adapted to be removably secured to said spout and having a dependent central stud, a domed primary valve member loosely mounted on said stud with an outwardly extending annular portion adapted to engage said primary valve seat, a spring compressed between said cap and said valve member and urging the latter downwardly, an inner annular shoulder formed on said valve member, said inner shoulder being substantially coplanar with the lower end of said stud when said outwardly extending portion engages said primary valve seat, a partition in said valve member spaced from and positioned below said shoulder, ports in said valve-member and said partition, and a free floating flexible secondary valve disc vertically movable between said inner shoulder and said partition and controlling said ports, said valve disc being movable from a first position at which said disc seats on said partition to a second position at which said disc engages said inner shoulder, said end of said stud providing a support for said disc when said disc engages said inner shoulder and said stud being movable downwardly against said disc to release said disc from said inner shoulder.

References Cited in the file of this patent UNITED STATES PATENTS 1,140,713 Price May 25, 1915 1,619,238 Buss Mar. 1, 1927 2,164,450 Eshbaugh et al July 4, 1939 2,266,314 Eshbaugh Dec. 16, 1941 2,528,791 Scoville Nov. 7, 1950 

